If the result of something is a close call, it is almost impossible to distinguish between the parties involved and to say who has won or whatever. It can also mean that you very nearly have a serious accident or get into trouble.
If an activity is referred to as a clutch play, it means that the activity was the key to the success or failure of the venture. For instance, a clutch play in a baseball game may be striking out a batter with the bases loaded.
It is the temperature range in which the body doesn't shiver or sweat, but has an idiomatic sense of a place where people feel comfortable, where they can avoid the worries of the world. It can be physical or mental.
Do what is required, come up to expectations. For example, Kate delivered the goods and got us the five votes we needed. This phrase alludes to delivering an order of groceries or other items. [Colloquial; second half of 1800s]